Harnessing the flexibility of Regular Expressions with Grep

There are two sides to grep – like any command, there’s the learning of syntax, the beginning
of which I covered in the grep tool tip. I’ll
come back to the syntax later, because there is a lot of it.

However, the more powerful side is grep‘s use of regular expressions. Again, there’s not room
here to provide a complete rundown, but it should be enough to cover 90% of usage. Once I’ve got a library
of grep-related stuff, I’ll post an entry with links to them all, with some covering text.

This or That

Without being totally case-insensitive (which -i) does,
we can search for “Hello” or “hello” by specifying the optional
characters in square brackets: